<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <title>6.判断字符串中是否包含指定字符</title>
  </head>
  <body>
    <script type="text/javascript" >
      let str = 'abcde'

      // const result = str.includes('')
      // console.log(result)

      // const result = str.indexOf('')
      // console.log(result)

    </script>
  </body>
</html>